US9764720B2 - Method for operating an electric motor for braking a vehicle, and control device for an electric motor designed at least for braking a vehicle - Google Patents

Method for operating an electric motor for braking a vehicle, and control device for an electric motor designed at least for braking a vehicle Download PDF

Info

Publication number
US9764720B2
US9764720B2 US15/165,575 US201615165575A US9764720B2 US 9764720 B2 US9764720 B2 US 9764720B2 US 201615165575 A US201615165575 A US 201615165575A US 9764720 B2 US9764720 B2 US 9764720B2
Authority
US
United States
Prior art keywords
electric motor
vehicle
speed change
setpoint speed
normal range
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
US15/165,575
Other languages
English (en)
Other versions
US20160355167A1 (en
Inventor
Andreas Erban
Jochen Feinauer
Bastian Richter
Michael Knoop
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Robert Bosch GmbH
Original Assignee
Robert Bosch GmbH
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Robert Bosch GmbH filed Critical Robert Bosch GmbH
Assigned to ROBERT BOSCH GMBH reassignment ROBERT BOSCH GMBH ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: Richter, Bastian, ERBAN, ANDREAS, KNOOP, MICHAEL, FEINAUER, JOCHEN
Publication of US20160355167A1 publication Critical patent/US20160355167A1/en
Application granted granted Critical
Publication of US9764720B2 publication Critical patent/US9764720B2/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
    • B60T8/00—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force
    • B60T8/17—Using electrical or electronic regulation means to control braking
    • B60T8/176—Brake regulation specially adapted to prevent excessive wheel slip during vehicle deceleration, e.g. ABS
    • B60T8/1761—Brake regulation specially adapted to prevent excessive wheel slip during vehicle deceleration, e.g. ABS responsive to wheel or brake dynamics, e.g. wheel slip, wheel acceleration or rate of change of brake fluid pressure
    • B60T8/17616—Microprocessor-based systems
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
    • B60L15/00—Methods, circuits, or devices for controlling the traction-motor speed of electrically-propelled vehicles
    • B60L15/20—Methods, circuits, or devices for controlling the traction-motor speed of electrically-propelled vehicles for control of the vehicle or its driving motor to achieve a desired performance, e.g. speed, torque, programmed variation of speed
    • B60L15/2009—Methods, circuits, or devices for controlling the traction-motor speed of electrically-propelled vehicles for control of the vehicle or its driving motor to achieve a desired performance, e.g. speed, torque, programmed variation of speed for braking
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
    • B60L7/00—Electrodynamic brake systems for vehicles in general
    • B60L7/24—Electrodynamic brake systems for vehicles in general with additional mechanical or electromagnetic braking
    • B60L7/26—Controlling the braking effect
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
    • B60T1/00—Arrangements of braking elements, i.e. of those parts where braking effect occurs specially for vehicles
    • B60T1/02—Arrangements of braking elements, i.e. of those parts where braking effect occurs specially for vehicles acting by retarding wheels
    • B60T1/10—Arrangements of braking elements, i.e. of those parts where braking effect occurs specially for vehicles acting by retarding wheels by utilising wheel movement for accumulating energy, e.g. driving air compressors
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
    • B60T13/00—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems
    • B60T13/10—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems with fluid assistance, drive, or release
    • B60T13/58—Combined or convertible systems
    • B60T13/585—Combined or convertible systems comprising friction brakes and retarders
    • B60T13/586—Combined or convertible systems comprising friction brakes and retarders the retarders being of the electric type
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
    • B60T13/00—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems
    • B60T13/74—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems with electrical assistance or drive
    • B60T13/748—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems with electrical assistance or drive acting on electro-magnetic brakes
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
    • B60L2240/00—Control parameters of input or output; Target parameters
    • B60L2240/10—Vehicle control parameters
    • B60L2240/12—Speed
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
    • B60L2240/00—Control parameters of input or output; Target parameters
    • B60L2240/40—Drive Train control parameters
    • B60L2240/42—Drive Train control parameters related to electric machines
    • B60L2240/423—Torque
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
    • B60L2240/00—Control parameters of input or output; Target parameters
    • B60L2240/40—Drive Train control parameters
    • B60L2240/46—Drive Train control parameters related to wheels
    • B60L2240/465—Slip
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
    • B60T2270/00—Further aspects of brake control systems not otherwise provided for
    • B60T2270/60—Regenerative braking
    • B60T2270/602—ABS features related thereto
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00—Road transport of goods or passengers
    • Y02T10/60—Other road transportation technologies with climate change mitigation effect
    • Y02T10/64—Electric machine technologies in electromobility
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00—Road transport of goods or passengers
    • Y02T10/60—Other road transportation technologies with climate change mitigation effect
    • Y02T10/72—Electric energy management in electromobility

Definitions

  • the present invention relates to a method for operating an electric motor for braking a vehicle. Moreover, the present invention relates to a control device for an electric motor which is designed at least for braking a vehicle. Furthermore, the present invention relates to an electric motor which is designed at least for braking a vehicle, and a braking system for a vehicle.
  • FIG. 1 shows a coordinate system for explaining a conventional method for decelerating a motor vehicle.
  • the conventional method for decelerating a motor vehicle is described in DE 10 2011 103 936 A1, for example.
  • the abscissa is a time axis t (in seconds).
  • the ordinate of the coordinate system in FIG. 1 depicts a wheel braking torque M (as the sum of both wheel braking torques of an axle) in newton meters.
  • a brake pressure buildup is begun in at least one wheel brake cylinder at a front axle of the motor vehicle.
  • the brake pressure buildup in the at least one wheel brake cylinder of the front axle, up to a friction braking torque Mhyd effectuated by the at least one wheel brake cylinder of the front axle, is equal to the braking request, but requires a comparatively long time (approximately 700 ms).
  • an electric motor which is designed for decelerating the motor vehicle is also controlled in such a way that the electric motor (immediately) effectuates a motor braking torque Mm for decelerating the motor vehicle.
  • the electric motor is controlled in such a way that effectuated motor braking torque Mm remains less than or equal to a limiting motor braking torque Mm 0 , above which a load on the electric motor exceeds the nominal load capacity (nominal load).
  • the aim is to be able to effectuate a total braking torque Mtotal (as the sum of friction braking torque Mhyd and motor braking torque Mm) which already exerts a braking effect on the motor vehicle immediately after reaction time ⁇ t 0 has elapsed.
  • the aim is for a braking distance of the motor vehicle that is to be decelerated to be reducible with the aid of the method depicted in FIG. 1 .
  • the present invention provides a method for operating an electric motor for braking a vehicle, a control device for an electric motor which is designed at least for braking a vehicle, an electric motor which is designed at least for braking a vehicle, and a braking system for a vehicle.
  • the present invention allows a significantly shortened braking distance, compared to the related art, during slowing/deceleration of a vehicle (to a standstill).
  • the shortening of the braking distance compared to the related art is achievable due to the fact that, with the aid of the present invention, an increased motor braking torque is effectuatable with the aid of the electric motor, in particular at the start of a slowing/deceleration of the motor vehicle.
  • the present invention is based, among other things, on the finding that, although a periodic load on the electric motor above the nominal load capacity is harmful to the electric motor and possibly to other vehicle components, an exceedance of the nominal load capacity solely in situations in which the requested setpoint speed change is outside the predefined normal range is possible without damage occurring.
  • the exceedance of the load on the motor may be utilized to effectuate a greater deceleration on the vehicle, at least during the overload operation time interval, with the aid of the electric motor (operated in the overload operation).
  • the vehicle may thus be decelerated quickly and with a reduced braking distance, in particular in emergency braking situations.
  • the electric motor is controlled in such a way that the load to be applied by the electric motor exceeds the nominal load capacity of the electric motor during the predefined overload operation time interval of 750 ms maximum.
  • the overload operation time interval may be set to be shorter than 500 ms, in particular shorter than 300 ms, and if desired, shorter than 200 ms, even shorter than 100 ms.
  • this is particularly advantageous when, in addition to the electric motor, the at least one wheel brake cylinder is also used for slowing/decelerating the vehicle. The vehicle may be slowed/decelerated even more quickly by the total braking torque, made up of the motor braking torque of the electric motor and the friction braking torque exerted by the at least one wheel brake cylinder.
  • the electric motor may be controlled in such a way that the load on the electric motor occurs above the nominal load capacity only until a friction braking torque of the at least one wheel brake cylinder which is sufficient for meeting the requested setpoint speed change may be expected.
  • the electric motor may thus be operated above the nominal load capacity, in particular during a phase in which a sufficient brake pressure is initially built up in the at least one wheel brake cylinder, while the electric motor experiences at most a load within the nominal load capacity as soon as the desired brake pressure is built up in the at least one wheel brake cylinder and a sufficient friction braking torque is available.
  • the electric motor may be deactivated beginning when the friction braking torque is sufficient, so that the at least one wheel brake cylinder takes over the further deceleration of the vehicle.
  • the load to be applied by the electric motor is preferably controlled above the nominal load capacity of the electric motor only until the estimated or ascertained variable exceeds a predefined or set limiting value, and/or a wheel slip is detected.
  • the limiting value may in particular be predefined or set in such a way that it corresponds to a limiting brake pressure or a limiting friction braking torque above which a wheel slip is likely.
  • the limiting value is advantageously set taking an instantaneous speed of the vehicle, an instantaneous longitudinal acceleration of the vehicle, and/or an instantaneous transverse acceleration of the vehicle into account. All of the variables listed here may influence the likelihood of occurrence of a wheel slip. By taking into account at least one of these variables in setting the limiting value, a reduction in a torque of the electric motor may take place without interfering with an ABS wheel control.
  • control device for an electric motor which is designed at least for braking a vehicle.
  • An electric motor which is designed at least for braking a vehicle, and a braking system for a vehicle, each including such a control device, likewise provide the advantages described above.
  • the control device according to the above-described specific embodiments of the method for operating an electric motor for braking a vehicle may be refined.
  • FIG. 1 shows a coordinate system for explaining a conventional method for decelerating a motor vehicle.
  • FIG. 2 shows a coordinate system for explaining a first specific embodiment of the method for operating an electric motor for braking a vehicle.
  • FIG. 3 shows a coordinate system for explaining a second specific embodiment of the method for operating an electric motor for braking a vehicle.
  • FIG. 4 shows a coordinate system for explaining a third specific embodiment of the method for operating an electric motor for braking a vehicle.
  • FIG. 5 shows a schematic illustration of one specific embodiment of the control device.
  • FIG. 2 shows a coordinate system for explaining a first specific embodiment of the example method for operating an electric motor for braking a vehicle.
  • the abscissa is a time axis t (in seconds).
  • the ordinate of the coordinate system in FIG. 2 depicts a wheel braking torque M (as the sum of both wheel braking torques of an axle) in newton meters.
  • the electric motor is controlled in such a way that the vehicle is slowed or decelerated (to a standstill) at least with the aid of a motor braking torque Mm exerted by the controlled electric motor on at least one wheel and/or at least one axle of the vehicle.
  • the electric motor which is operated for carrying out the method described here may be, for example, an electric motor that is suitable for generator mode/recuperative braking of the vehicle.
  • a kinetic energy of the vehicle may be converted into electrical energy, which is utilized for charging an energy store/a battery.
  • the electric motor may be designed as a drive motor in such a way that it is optionally usable also for accelerating the vehicle.
  • the electric motor may also be an axle drive of the vehicle which is connected to an axle differential and two wheels to be driven (for example, wheels of the front axle).
  • the electric motor may also be used in an electromechanical brake booster which is connected upstream from a brake master cylinder of a hydraulic braking system of the vehicle.
  • the electric motor may be a motor of a plunger that is used in the hydraulic braking system. In all cases described here, the electric motor has more advantageous dynamics than conventional hydraulic braking systems.
  • implementation of the method described here is not limited to one of the types of the operated electric motor mentioned here.
  • multiple individual motor units may also be operated as “the electric motor” when carrying out the method described here.
  • the vehicle/motor vehicle which is slowed/decelerated (to a standstill) with the aid of the particular electric motor is not limited to a certain type of vehicle or motor vehicle.
  • the electric motor may be used in a number of various hybrid or electric vehicles.
  • the method described here is well suited for carrying out autonomous braking, i.e., braking which is requested not by a driver of the vehicle, but, rather, by an autonomous automatic system of the vehicle (an emergency braking system and/or an automatic speed control system, for example).
  • autonomous braking autonomous emergency braking (AEB)
  • AEB autonomous emergency braking
  • HBA hydraulic braking assistant
  • the method described here may therefore also increase a safety standard of non-driver-controlled autonomous driving of the particular vehicle.
  • all of the types of motors mentioned above are well suited for automatic slowing or deceleration of the vehicle thus equipped, due to their advantageous dynamics.
  • the electric motor is controlled with regard to a requested setpoint speed change, taking at least one default signal into account.
  • the requested setpoint speed change may be requested by the driver of the vehicle (by actuating a brake actuating element/brake pedal and/or an accelerator pedal) as well as by the autonomous automatic control system of the vehicle.
  • the at least one default signal concerning the requested setpoint speed change may be, for example, at least one signal of a brake actuating element sensor, such as a pedal travel sensor, a rod travel sensor, a differential travel sensor, and/or a driver brake force sensor, an accelerator pedal sensor, and/or the autonomous automatic control system.
  • an ascertainment is made, based on the at least one default signal, whether the requested setpoint speed change is in a predefined normal range.
  • the normal range is preferably defined such that only emergency braking is outside the normal range. Thus, taking the at least one default signal into account, it may be ascertained whether the requested setpoint speed change indicates emergency braking.
  • a rapid/sudden interruption in the actuation of the accelerator pedal and/or a rapid/sudden actuation of the brake actuating element/brake pedal may be an indication of a requested setpoint speed change outside the normal range.
  • a magnitude of the requested setpoint speed change may be an indication that it is outside the predefined normal range.
  • the at least one default signal for the requested setpoint speed change is a signal of an emergency braking system, and therefore the setpoint speed change is outside the normal range.
  • emergency braking is recognizable as such with a relatively low error rate.
  • the electric motor is controlled in such a way that a load to be applied by the electric motor remains less than or equal to a nominal load capacity (a nominal load) of the electric motor.
  • the electric motor is controlled in such a way that a motor braking torque Mm effectuated by the electric motor (during the overall requested slowing or deceleration of the vehicle) remains less than or equal to a limiting motor braking torque Mm 0 , above which the load on the electric motor exceeds the nominal load capacity.
  • a pattern of the motor braking torque Mm in a situation in which the requested setpoint speed change is in the predefined normal range is illustrated in the coordinate system in FIG. 1 .
  • the coordinate system in FIG. 2 shows an example of a situation in which the requested setpoint speed change is outside the predefined normal range.
  • the electric motor is controlled in such a way that the load to be applied by the electric motor exceeds the nominal load capacity of the electric motor, at least during a predefined overload operation time interval ⁇ t 1 .
  • the electric motor is controlled in such a way that a motor braking torque Mm effectuated by the electric motor is above limiting motor braking torque Mm 0 , at least during predefined overload operation time interval ⁇ t 1 .
  • the electric motor may be operated with full utilization of its resources.
  • the electric motor may already effectuate a motor braking torque Mm above limiting motor braking torque Mm 0 for braking the vehicle, (virtually) immediately after the request for the setpoint speed change (i.e., after a communication-related reaction time ⁇ t 0 of 60 ms, for example, has elapsed).
  • This may be utilized in a targeted manner for preventing accidents in emergency braking situations, in that a braking distance of the vehicle is shortened by temporarily overloading the electric motor.
  • the number of setpoint changes in speed to be expected outside the predefined normal range is comparatively small (in particular in relation to the service life of the vehicle). Due to the infrequent operation of the electric motor in its overload operation (at least during the predefined overload operation time interval ⁇ t 1 ), it is thus possible to achieve a much higher motor braking torque Mm than nominal in a targeted manner in emergency braking situations, without having to accept damage to the electric motor and/or to some other vehicle component.
  • At least one wheel brake cylinder of a hydraulic braking system of the vehicle is also used for slowing/decelerating the vehicle.
  • the at least one wheel brake cylinder (or the hydraulic braking system equipped with same) has a greatly delayed responsiveness/dynamics compared to the electric motor.
  • the electric motor may be utilized for bridging a phase of overcoming the clearance and/or of the brake pressure buildup in the at least one wheel brake cylinder via its overload operation, so that a significant total braking torque Mtotal (made up of motor braking torque Mm and friction braking torque Mhyd) may be exerted earlier on the vehicle in order to decelerate it.
  • the electric motor is therefore preferably controlled in such a way that it operates in overload operation primarily in the phase of overcoming the clearance and/or of the brake pressure buildup.
  • the electric motor is preferably controlled in such a way that it is transferred into its overload operation immediately after recognition that the setpoint speed change is outside the normal range.
  • At least one estimated or ascertained variable concerning friction braking torque Mhyd (instantaneously) exerted by the at least one wheel brake cylinder of the hydraulic braking system of the vehicle is advantageously also taken into account.
  • the at least one estimated or ascertained variable may be, for example, the brake pressure present in the at least one wheel brake cylinder, and/or friction braking torque Mhyd.
  • the overload operation of the electric motor (or overload operation time interval ⁇ t 1 ) may in particular be timed in such a way that the electric motor is operated above its nominal load capacity only for bridging the phase of overcoming the clearance and/or of the brake pressure buildup in the at least one wheel brake cylinder. Damage to the electric motor or some other vehicle component is reliably prevented in such short-term utilization of the overload operation of the electric motor.
  • the braking effect of the electric motor may be used in a targeted manner in such a way that the achieved deceleration of the vehicle is increased with the aid of total braking torque Mtotal.
  • the limited dynamics of a hydraulic pressure rise in the at least one wheel brake cylinder is bridged with the aid of the overload operation of the electric motor.
  • it is still ensured that no damage to the electric motor or to some other vehicle component occurs.
  • FIG. 3 shows a coordinate system for explaining a second specific embodiment of the method for operating an electric motor for braking a vehicle.
  • the abscissa depicts a time axis t (in seconds), while the ordinate of the coordinate system in FIG. 3 depicts a wheel braking torque M (as the sum of both wheel braking torques of an axle) in newton meters.
  • the electric motor is controlled in such a way that the load to be applied by the electric motor remains less than or equal to the nominal load capacity of the electric motor. Only if the requested setpoint speed change is outside the predefined normal range is the electric motor controlled, in the method depicted in FIG. 3 , in such a way that the load to be applied by the electric motor exceeds the nominal load capacity of the electric motor (graph Mm) (only) during predefined overload operation time interval ⁇ t 1 of 750 milliseconds (ms) maximum.
  • the method depicted in FIG. 3 also achieves advantageous protection of the electric motor despite its brief operation above the nominal load capacity.
  • the electric motor is operated in overload operation for overload operation time interval ⁇ t 1 .
  • the electric motor is controlled in such a way that the load to be applied by the electric motor is regulated in such a way that it is less than or equal to the nominal load capacity of the electric motor.
  • motor braking torque Mm effectuated by the electric motor is therefore returned at most to limiting motor braking torque Mm 0 .
  • the temporary overloading of the electric motor during overload operation time interval ⁇ t 1 may also be referred to as transient overshoot.
  • Overload operation time interval ⁇ t 1 may be set to be shorter than 500 milliseconds (ms), in particular shorter than 300 milliseconds (ms), and if desired, shorter than 200 milliseconds (ms), even shorter than 100 milliseconds (ms).
  • other curves k 1 or k 2 may also be predefined for the transient overshoot.
  • Optimal step responses may thus be generated as a profile of motor braking torque Mm, in accordance with the needs of the particular drive train of the electric motor.
  • the braking distance of the vehicle may be shortened in all cases due to equal-area compensation.
  • the method depicted in FIG. 3 thus achieves rapid emergency braking of a vehicle, in particular in an emergency braking situation.
  • No friction braking torque Mhyd of at least one wheel brake cylinder is plotted in the coordinate system in FIG. 3 .
  • the method depicted in FIG. 3 may optionally be refined in such a way that the at least one wheel brake cylinder of the hydraulic braking system is also used for slowing/decelerating the vehicle. Further features/method steps of the specific embodiment in FIG. 2 may also be transferred to the method in FIG. 3 .
  • FIG. 4 shows a coordinate system for explaining a third specific embodiment of the method for operating an electric motor for braking a vehicle.
  • abscissa and the ordinate of the coordinate system in FIG. 4 reference is made to the preceding figures.
  • the electric motor together with the at least one wheel brake cylinder of the hydraulic braking system is utilized for slowing/decelerating the vehicle.
  • the at least one estimated or ascertained variable Mhyd is also taken into account with regard to friction braking torque Mhyd (instantaneously) exerted by the at least one wheel brake cylinder of the hydraulic braking system.
  • the load to be applied by the electric motor (after communication-related reaction time ⁇ t 0 ) is controlled above the nominal load capacity of the electric motor only until estimated or ascertained variable Mhyd exceeds a predefined or set limiting value Mmax, and/or a wheel slip is detected. It may thus be ensured that an antilock braking system (ABS) control possibly to be carried out is not adversely affected by an increased torque of the electric motor.
  • ABS antilock braking system
  • the braked wheels therefore do not have excessively high brake slips. Steerability of the vehicle is thus ensured.
  • measured or estimated friction braking torque Mhyd as estimated or ascertained variable Mhyd is compared to predefined or set limiting value Mmax.
  • the (estimated or measured) brake pressure present in the at least one wheel brake cylinder may likewise also be evaluated as estimated or ascertained variable Mhyd.
  • the load to be applied by the electric motor may also be controlled above the nominal load capacity of the electric motor until a wheel slip threshold is exceeded. The occurrence of wheel slip may be detected at an antilock braking system (ABS) bit, for example.
  • ABS antilock braking system
  • the electric motor previously operated in its overload operation, is deactivated as soon as estimated or ascertained variable Mhyd exceeds predefined or set limiting value Mmax, and/or a wheel slip is detected.
  • the vehicle is then decelerated (to a standstill) for a residual braking time ⁇ t 2 without using the electric motor.
  • the operating point of the ABS controller is (generally) maintained by a ramp-like turn-off of motor braking torque Mm of the electric motor.
  • Limiting value Mmax for the at least one variable Mhyd may be predefined or set in such a way that, beginning when the at least one variable Mhyd is equal to limiting value Mmax, a wheel slip may occur with increased likelihood.
  • limiting value Mmax may be a limiting brake pressure and/or a limiting friction braking torque Mmax, above which the occurrence of a wheel slip is likely.
  • the limiting value is set by taking an instantaneous speed of the vehicle, an instantaneous longitudinal acceleration of the vehicle, and/or an instantaneous transverse acceleration of the vehicle into account. All of the advantages described above are achieved in this way.
  • a decrease in motor braking torque Mm of the electric motor may take place so that it matches the hydraulic brake pressure modulation of the ABS system which has just been carried out.
  • a pressure reduction takes place in at least one of the wheel brake cylinders of the driven axle.
  • the ABS system may then individually control individual braking torques M 1 and M 2 of the wheel brake cylinders of the driven axle in a known manner.
  • a braking distance until the vehicle is completely decelerated may be easily shortened with the aid of all of the methods described above. All methods are suited for modular use in existing ESP systems which include known ABS control processes. If the methods require friction braking torques Mhyd or the brake pressures in the wheel brake cylinders of the driven wheels, these variables are generally available in the ESP/ABS system. In addition, these variables may be easily measured.
  • All methods described here are also suitable for AEB braking maneuvers for operating the particular electric motor in generator mode.
  • the output variables and the setpoint values may be transmitted via the vehicle network to an inverter, where they are measurable as achieved values for the torque and the speed of the electric motor.
  • the individual components of the particular active chain of the recuperation system are not operated at their respective absolute load limit during normal operation. This results in a comparatively long service life of the individual components.
  • any of the above-described methods may be utilizable for effectuating an additional braking potential which is usable for a short period of time.
  • the charge management of the drive battery may take place in such a way that a resulting one-time energy input is possible at any time, at least in the brief phase of the hydraulic brake pressure buildup during an emergency braking situation.
  • the electric motor depending on the design, could optionally be operated in the so-called active short circuit (ASC) mode. In this case, the motor braking torque is converted into heat in the electric motor. Since this operating mode is carried out only briefly, there is no concern for thermal overload of the electric motor. Thus, destruction of the electric motor remains precluded.
  • FIG. 5 shows a schematic illustration of one specific embodiment of the control device.
  • Control device 10 schematically illustrated in FIG. 5 , together with an electric motor 12 , is usable in a number of various types of braking systems. It is pointed out that a utilization of control device 10 is not limited to a certain type of electric motor 12 .
  • Control device 10 includes an electronics unit 14 which is designed for receiving at least one provided default signal 16 concerning a setpoint speed change requested by a driver of the vehicle or an autonomous automatic control system of the vehicle. Examples of the at least one receivable default signal 16 have already been mentioned above.
  • the electronics unit is also designed for controlling electric motor 12 with the aid of at least one control signal 18 , taking into account the at least one provided default signal 16 , in such a way that a motor braking torque is exertable on at least one wheel and/or at least one axle of the vehicle with the aid of controlled electric motor 12 .
  • the vehicle may thus be slowed or decelerated at least with the aid of the motor braking torque of electric motor 12 .
  • electronics unit 14 is additionally designed for recognizing whether the requested setpoint speed change is in a predefined normal range, taking the at least one default signal 16 into account. If the requested setpoint speed change is in the predefined normal range, electric motor 12 is controllable by electronics unit 14 in such a way that a load to be applied by electric motor 12 remains less than or equal to a nominal load capacity of electric motor 12 . In contrast, if the requested setpoint speed change is outside the predefined normal range, electronics unit 14 is designed for controlling electric motor 12 in such a way that the load to be applied by electric motor 12 exceeds the nominal load capacity of electric motor 12 , at least during a predefined overload operation time interval.
  • control device 10 also provides all of the advantages described above.
  • electronics unit 14 may additionally be designed for controlling electric motor 12 in such a way that the load to be applied by electric motor 12 exceeds the nominal load capacity of electric motor 12 during the predefined (set) overload operation time interval of 750 ms maximum.
  • electronics unit 14 is designed for also taking into account at least one provided or self-determined variable 20 concerning a friction braking torque instantaneously exerted by at least one wheel brake cylinder of a hydraulic braking system of the vehicle, during control of electric motor 12 .
  • electronics unit 14 may also be designed for controlling electric motor 12 in such a way that the load to be applied by electric motor 12 is above the nominal load capacity of electric motor 12 only until the provided or self-determined variable 20 exceeds a predefined or set limiting value, and/or a wheel slip signal 22 regarding a wheel slip that is instantaneously present is received by electronics unit 14 .
  • Wheel slip signal 22 may be an antilock braking system (ABS) bit, for example.
  • ABS antilock braking system
  • the limiting value for the at least one variable 20 may (as the wheel brake slip threshold) be predefined or set in such a way that, beginning when the at least one variable 20 is equal to the limiting value, a wheel slip may occur (with increased likelihood).
  • the limiting value may be set, (in particular by electronics unit 14 ), taking an instantaneous speed of the vehicle, an instantaneous longitudinal acceleration of the vehicle, and/or an instantaneous transverse acceleration of the vehicle into account.
  • An electric motor 12 which is designed at least for braking a vehicle and which includes such a control device 10 , as well as a braking system for a vehicle which includes such a control device 10 , also provide all the advantages mentioned above.

Landscapes

  • Engineering & Computer Science (AREA)
  • Transportation (AREA)
  • Mechanical Engineering (AREA)
  • Power Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Fluid Mechanics (AREA)
  • Electromagnetism (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Regulating Braking Force (AREA)
US15/165,575 2015-06-02 2016-05-26 Method for operating an electric motor for braking a vehicle, and control device for an electric motor designed at least for braking a vehicle Active US9764720B2 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
DE102015210104.5A DE102015210104A1 (de) 2015-06-02 2015-06-02 Verfahren zum Betreiben eines Elektromotors zum Bremsen eines Fahrzeugs und Steuervorrichtung für einen zumindest zum Bremsen eines Fahrzeugs ausgelegten Elektromotor
DE102015210104 2015-06-02
DE102015210104.5 2015-06-02

Publications (2)

Publication Number Publication Date
US20160355167A1 US20160355167A1 (en) 2016-12-08
US9764720B2 true US9764720B2 (en) 2017-09-19

Family

ID=57352395

Family Applications (1)

Application Number Title Priority Date Filing Date
US15/165,575 Active US9764720B2 (en) 2015-06-02 2016-05-26 Method for operating an electric motor for braking a vehicle, and control device for an electric motor designed at least for braking a vehicle

Country Status (2)

Country Link
US (1) US9764720B2 (de)
DE (1) DE102015210104A1 (de)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10576839B2 (en) 2018-08-01 2020-03-03 Toyota Motor Engineering & Manufacturing North America, Inc. Motor lock overheat mitigation control for autonomous vehicles

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102016007012B4 (de) * 2016-06-09 2018-07-19 Audi Ag Verfahren zum Unterstützen eines Fahrers
DE102016123350B4 (de) * 2016-12-02 2019-06-19 Saf-Holland Gmbh Sattelauflieger, Sattelzug und Verfahren zum Bremsen eines Sattelaufliegers
DE102019211841A1 (de) * 2019-08-07 2021-02-11 Robert Bosch Gmbh Verfahren zum Bremsen eines elektrisch angetriebenen Fahrzeugs sowie Fahrzeug
CN114981136A (zh) * 2020-01-15 2022-08-30 沃尔沃卡车集团 一种用于控制车辆制动系统的方法
CN112389275B (zh) * 2020-11-16 2022-03-29 睿驰电装(大连)电动系统有限公司 基于电驱主动发热模式的安全控制方法和装置

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20050218718A1 (en) * 2004-04-06 2005-10-06 Toyota Jidosha Kabushiki Kaisha Deceleration control apparatus and method for a vehicle
US20090066273A1 (en) * 2007-09-10 2009-03-12 Randy Dunn Regenerative torque shifter
US20100324766A1 (en) * 2007-11-09 2010-12-23 Societe De Technologie Michelin System for generating an estimation of the ground speed of a vehicle from measures of the rotation speed of at least one wheel
DE102011103936A1 (de) 2011-06-10 2012-12-13 Audi Ag Verfahren und Vorrichtung zum Abbremsen eines Kraftfahrzeugs
US20130331231A1 (en) * 2011-03-14 2013-12-12 Karl Redbrandt Method and system pertaining to determination of a contact point for a clutch
US20160257222A1 (en) * 2015-03-06 2016-09-08 Honda Motor Co., Ltd. Vehicle parking control device

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20050218718A1 (en) * 2004-04-06 2005-10-06 Toyota Jidosha Kabushiki Kaisha Deceleration control apparatus and method for a vehicle
US20090066273A1 (en) * 2007-09-10 2009-03-12 Randy Dunn Regenerative torque shifter
US20100324766A1 (en) * 2007-11-09 2010-12-23 Societe De Technologie Michelin System for generating an estimation of the ground speed of a vehicle from measures of the rotation speed of at least one wheel
US20130331231A1 (en) * 2011-03-14 2013-12-12 Karl Redbrandt Method and system pertaining to determination of a contact point for a clutch
DE102011103936A1 (de) 2011-06-10 2012-12-13 Audi Ag Verfahren und Vorrichtung zum Abbremsen eines Kraftfahrzeugs
US20160257222A1 (en) * 2015-03-06 2016-09-08 Honda Motor Co., Ltd. Vehicle parking control device

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10576839B2 (en) 2018-08-01 2020-03-03 Toyota Motor Engineering & Manufacturing North America, Inc. Motor lock overheat mitigation control for autonomous vehicles

Also Published As

Publication number Publication date
DE102015210104A1 (de) 2016-12-08
US20160355167A1 (en) 2016-12-08

Similar Documents

Publication Publication Date Title
US9764720B2 (en) Method for operating an electric motor for braking a vehicle, and control device for an electric motor designed at least for braking a vehicle
US8494745B2 (en) Motor vehicle braking system having a hydraulically actuated service braking system and an electromechanically actuated braking system
US10647205B2 (en) Braking control apparatus
EP2570315B1 (de) Regeneratives Bremssystem für ein Hybrid-Elektrofahrzeug und entsprechendes Verfahren
US11110802B2 (en) Method for operating a regenerative braking system of a vehicle and control unit for a regenerative braking system of a vehicle
EP2987693B1 (de) Bremsvorrichtung eines fahrzeugs
US20170113700A1 (en) Vehicle Control Apparatus and Vehicle Control Method
US20060225971A1 (en) Braking a vehicle in the context of an emergency stop
US9895978B2 (en) Braking force control method for vehicle
CN106926709B (zh) 制动能量回收装置、方法及轻型电动车
CN111086394A (zh) 至少暂时电驱动的车辆的制动系统、机动车和制动控制方法
US10343531B2 (en) Control device for a regenerative braking system and method for operating a regenerative braking system
KR101339245B1 (ko) 능동형 브레이크 시스템 및 그것의 제어방법
CN106314408B (zh) 运行具有电动机的制动系统的方法和电动机的控制设备
JP6134385B2 (ja) 車両用のブレーキ制御装置および車両用の少なくとも１つの電気駆動モータを運転する方法
US11970169B2 (en) Anti-lock control method and anti-lock control system for a braking system of a vehicle
Kant Sensotronic brake control (SBC)
CN110072745B (zh) 用于运行机动车的方法和装置、机动车
CN112105531A (zh) 用于电驱动的车辆的系统以及具有该系统的车辆和对此的方法
US11554761B2 (en) Method for controlling an electromechanical braking system and electromechanical braking system
KR102487781B1 (ko) 차량용 회생 제동 시스템 및 차량의 회생 제동 시스템을 작동시키기 위한 방법
US10940841B2 (en) Method and control unit for controlling a hydraulic braking system
KR20200077036A (ko) 전기차용 비상 제동 시스템 및 비상 제동 방법
CN117864082A (zh) 确定车辆的车轮的制动力方法、装置、设备、车辆和产品
KR20190054156A (ko) 자동차를 작동하기 위한 방법 및 장치, 그리고 자동차

Legal Events

Date Code Title Description
AS Assignment

Owner name: ROBERT BOSCH GMBH, GERMANY

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:ERBAN, ANDREAS;FEINAUER, JOCHEN;RICHTER, BASTIAN;AND OTHERS;SIGNING DATES FROM 20160607 TO 20160711;REEL/FRAME:039435/0336

STCF Information on status: patent grant

Free format text: PATENTED CASE

MAFP Maintenance fee payment

Free format text: PAYMENT OF MAINTENANCE FEE, 4TH YEAR, LARGE ENTITY (ORIGINAL EVENT CODE: M1551); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY

Year of fee payment: 4